The present invention relates to cleaning compositions, and to a method of cleaning using such compositions, which contain certain proteases produced by microorganisms of the genus Vibrio. It particularly relates to laundry detergents, bleaches, automatic dishwasher detergents, and laundry pre-soak compositions which contain such Vibrio proteases.
Protease-containing cleaning compositions are well known in the art. Such compositions are commercially available, and are described in a large body of art. Representative of this literature are U.S. Pat. Nos. Re. 30,602; 3,553,139; 3,674,643; 3,697,451; 3,748,233; 3,790,482; 3,827,938; 3,871,963; 3,931,034; 4,162,987; 4,169,817; 4,287,101; 4,429,044; 4,480,037; 4,511,490, 4,515,705 and 4,543,333; as well as Innovations in Biotechnology, edited by E. H. Houwink and R. R. van der Meer, pages 31 to 52 (Elsevier Science Publishers, Amsterdam, 1984).
A major trend in the detergent industry is for manufacturers to develop phosphate-free products that function at low wash temperatures. In addition, liquid laundry detergents are increasingly popular with consumers. As a result of these changes in the formulation of detergent compositions, detergent makers have increasingly turned to the use of enzymes in order to compensate for reductions in cleaning power.
In order to be useful as a detergent enzyme, it is desirable for a protease to possess high activity on proteinaceous substances over a wide pH and temperature range; good alkaline stability; stability in the presence of surfactants, builders, oxidizing agents and other detergent components; and good storage (shelf-life) stability. The need for stability in the presence of other detergent components has become particularly important with the evolution of multifunctional products which contain, e.g., built-in bleaches, fabric softeners, etc.
The most widely employed proteases in cleaning compositions are the alkaline proteases derived from various strains of Bacillus. Such proteases, which are marketed under tradenames such as and Esperase.TM. and Alcalase.TM. from Novo Laboratories, Wilton, Conn. and Maxatase.TM. and Maxacal.TM. from Gist-Brocades, Chattanooga, Tenn., have desirable alkaline stability properties and proteolytic activities. The temperature optima of these enzymes, however, is about 60.degree.-70.degree. C., which is above the normal temperatures used for warm (30.degree.-40.degree. C.) and cool (15.degree.-30 + C.) water washings. Moreover, the Bacillus alkaline proteases have less than desirable stability to oxidizing agents, and are completely unstable in chlorine bleaches, which precludes their use with chlorine bleaches, automatic dishwasher detergents, etc.
As a result of these deficiencies in the properties of the Bacillus alkaline proteases, the art has attempted to develop alternative alkaline proteases such as the alkaline serine protease produced by Flavobacterium arborescens, described in U.S. Pat. No. 4,429,044. Another approach to this problem has been to modify the known Bacillus alkaline proteases, using recombinant DNA technology and site-directed mutagenesis, to improve the stability of the enzymes. In this regard, see, e.g., Estell et al., J. Biological Chemistry, Vol. 260, No. 11, pages 6518-6521, (1985); European Published Patent Application No. 130 756, dated Jan. 9, 1985; and PCT Published Application No. WO 87/04461, dated July 30, 1987.
It has also been suggested that various neutral proteases may be employed in detergent applications. See, e.g., U.S. Pat. No. 4,511,490; Cowan et al., Trends in Biotechnology, Vol. 3, No. 3, pages 68-72 (1985); and Keay et al., Biotechnology and Bioengineering, Vol. XII, pages 179-212 (1970). However, as indicated by the latter two articles, the neutral proteases which have heretofore been tested in detergent applications have reduced activities at the alkaline pH values normally present during detergent use, and poor stability to oxidizing agents.
In addition to the various enzymes discussed above, a multitude of different proteases are known for use in other (i.e., non-detergent) applications. Commonly assigned, co-pending U.S. patent application Ser. No. 83,741, filed Aug. 7, 1987, for example, describes the use of a protease produced by Vibrio proteolyticus (ATCC 53559) (hereinafter referred to as "vibriolysin") to mediate peptide bond formation. A large number of various other proteases and their respective utilities are also described in Cowan et al., Trends in Biotechnology, Vol. 3, No. 3, pages 68-72 (1985). Despite the existence of this multitude of known proteases, recombinant DNA technology, etc., however, the prior art has yet to develop proteases completely satisfactory for use in modern cleaning formulations.